3-dimension stresses and new failure model to predict behavior of clay soils in various liquid limit ranges

Abstract

Data analytics are becoming important to better characterize the material behavior. In this study, over 3000 data from the laboratory studies and literature for the field soils were analyzed to quantify the relationship between the density, natural moisture content, shear strength, deviatoric shear stress at failure (3-dimension stress) with the liquid limit (LL). With the increase in the construction of wells, tunnels, piles, and storage facilities, there is interest in determining the safety of soils under multiaxial loading. The range of liquid limit (LL) for the soil investigated varied from 20 to 60%. The ranges of the dry density (γd) and the natural moisture content (MC) for the soils varied from 1.2 to 2.6 g/cm3 and 13 to 56% respectively. The statistical distribution of the data collected varied from normal distribution to Weibull distribution. Vipulanandan correlation model correlated some of the physical properties of the soils. Vipulanandan failure model was used to the failure stresses for the soil and compared to the Mohr-Coulomb failure model and other failure models. Based on the coefficient of determination and root mean square error, the Vipulanandan failure model predicted the results more reliable than the other models. Vipulanandan failure model also predicted the maximum shear strength limit and maximum second deviatoric stress invariant for the soil, whereas none of the other models predicted the maximum shear tolerance for the soil investigated. With the Vipulanandan failure model, the maximum shear strength predicted for the soil was 57 kPa. The maximum second deviatoric stress invariant for the soil in the LL range of 20 and 60% varied from 44 to 30 kPa.